This invention relates to vehicle windshield cleaning apparatus having both washer and wiper motors, and particularly to such apparatus having minimal signal connections through the vehicle firewall from the operator control to the wiper and washer motors. It is desirable to minimize the signal connections as much as possible to reduce the cost and complexity of the vehicle wiring harnesses. This invention contributes to such reduction by combining wiper and washer motor actuating signals on a single, voltage multiplexed connection between separate actuating switches on the passenger side of the firewall and the washer and wiper motor circuitry on the engine side.